纳米银粉在水溶液中的分散及粒径表征

Dispersion and Particle Size Analysis of Silver Nano-particles in Aqueous Medium

利用直流电弧等离子体蒸发冷凝法制备纳米银粉,采用X射线衍射分析对纳米银粉的结构进行表征,采用纳米激光粒度仪研究不同超声分散工艺与不同离子类型的分散剂聚乙烯吡咯烷酮、十六烷基三甲基溴化氨、十二烷基硫酸钠对纳米银粉在水溶液中分散性能的影响,获得纳米银粉的最佳分散工艺与激光粒径分布,对比研究纳米银粉的激光粒径与透射电镜统计的粒径的差异。结果表明:纳米银颗粒为立方晶系多晶体,颗粒的结晶性良好;以十六烷基三甲基溴化氨为分散剂的效果最理想,最佳超声波功率为600 W;当十六烷基三甲基溴化氨的质量浓度为0.5 g/L时,纳米银颗粒的分散稳定性较好;激光粒径反映的纳米颗粒的动态二次粒径略大于从透射电镜图像统计得到的粒径。

Silver nano-particles were prepared by direct current arc plasma evaporation method. The structure of silver nano-partieles was analyzed by XRD. The effects of ultrasonic dispersion process and different dispersants including polyvinylpyrrolidone, cetyltrimethyl ammonium bromide and sodium dodecyl sulfate for dispersing performance of silver nano-particles aqueous suspensions were studied by laser nano-particle size instrument. The best dispersing process and laser particle size distribution were obtained. The difference of silver nano-particles between laser particle size and TEM statistics particle size was comparatively studied. The results show that the silver nano-particles belong to polycrystalline cubic crystal system with good crystalline. The best dispersant is cetyltrimethyl ammonium bromide and the best ultrasonic power is 600 W. The dispersion stability of the sample is fine when the mass concentration of cetyltrimethyl ammonium bromide is 0.5 g/L. The laser particle size is a dynamic secondary particle size, which is little larger than the TEM statistics particle size.